The distribution of organic contaminant in aged tar-oil contaminated soils

One of the most common soil contamination sources in Germany are former manufactured gas plants. Many of them were destroyed during the World War II or abandoned in late XXth century. As the result a lot of potentially fertile soils were contaminated with specific viscous tar oil wastes. We studied a small tar oil waste basin. The age of the contamination was assessed to be at least 30 years. Natural attenuation processes resulted in formation of three soil layers. The upper layer (about 7cm in thickness) was rooted by weak grass vegetation and had features of newly formed humic-like organic matter. The total petroleum hydrocarbon (TPH) content was 28 mg/g. Below this layer (7-15 cm) we observed the most contaminated stratum with 90 mg/g TPH. The layer underneath (15-22 cm) had smaller concentrations of 16 mg/g TPH. Underlying strata had no visual evidence of contamination. Microbial biomass analyses showed that the most contaminated layer had 2-3 times more bacteria than the control soils. We suppose that during the aging processes a new microbial consortium capable of transforming high-molecular weight hydrocarbons has developed. Optical and FTIR-microscopy allowed us to observe the microstructure of contaminated soils. The tar oil formed dense spherical aggregates within the soil, which contained almost no mineral phase. Root channels and macropores were identified as preferential pathflows for the viscous tar oil, as they seemed to be coated with hydrocarbons even in less contaminated underlayers. We presume that open pores could initially act as remediation spots with aerobic conditions. Future oil migration might clog these pores, cease oxidation processes and slow down the remediation. High contents of total Fe and both dithionite-extractable and oxalate-extractable Fe as well as the occurrence of large siderite crystals in the most contaminated layer suggested that there might be isolated zones with anaerobic conditions to support this assumption

Dynamik von mikrobiellen Gemeinschaften in zeitweise überfluteten Böden mit und ohne Zugabe von Biokohle

Böden in Auen werden zeitweise überflutet, was eine Änderung des Redoxpotentials bewirkt. Diese variierenden Umweltbedingungen können Bodenmikroorganismen erheblichen Stress aussetzen, vor allem, wenn diese Schwankungen den physiologischen Toleranzbereich der Organismen überschreiten. Mikroorganismen setzen verschiedenste Anpassungs- und Vermeidungsstrategien ein, um in solchen Situationen überleben zu können. Hierdurch verändert sich die Zusammensetzung der bodenmikrobiellen Gemeinschaft, was wiederum Rückkopplungseffekte auf die biogeochemischen Eigenschaften des Bodens ausübt. Um Böden und deren Eigenschaften zu verbessern, werden seit einigen Jahren verschiedene Biokohlen eingesetzt. Welche bodenmikrobiellen Prozesse im Boden von der Biokohle auf welche Art beeinflusst werden, ist jedoch weitestgehend ungeklärt. Ziel dieser Studie war es, den Einfluss verschiedener Biokohlen und wechselnder Redoxverhältnisse auf die bodenmikrobielle Gemeinschaft in einem zeitweise überfluteten Boden zu untersuchen. Dazu wurden Bodenproben der Wupper mit unterschiedlichen Biokohlen im Laborversuch vermischt und vorinkubiert. Die eingesetzten Biokohlen BC200 und BC500 unterschieden sich in der Pyrolysetemperatur (200°C und 500°C). Die so vorbehandelten Böden wurden anschließend in biogeochemischen Mikrokosmen bei vordefinierten Redoxpotentialen inkubiert. Anschließend wurde die Dynamik der bodenmikrobiellen und der bakteriellen Gemeinschaft (PLFA und DGGE) bestimmt. Die Ergebnisse zeigen, dass sowohl die Änderung des Redoxpotentials, als auch die Zugabe von Biokohle die Zusammensetzung der mikrobiellen und bakteriellen Gemeinschaft in Bezug auf Gesamtzahl, aber auch nach taxonomischer Gruppe, verändern. Bestimmte mikrobielle Gruppen und Spezies werden gefördert bzw. unterdrückt. Möglicherweise lassen sich durch die Aufklärung dieser Zusammenhänge Vorhersagen zu Folgen bei Überflutungsereignissen treffen

Links between maternal postpartum depressive symptoms, maternal distress, infant gender and sensitivity in a high-risk population

<p>Abstract</p> <p>Background</p> <p>Maternal postpartum depression has an impact on mother-infant interaction. Mothers with depression display less positive affect and sensitivity in interaction with their infants compared to non-depressed mothers. Depressed women also show more signs of distress and difficulties adjusting to their role as mothers than non-depressed women. In addition, depressive mothers are reported to be affectively more negative with their sons than with daughters.</p> <p>Methods</p> <p>A non-clinical sample of 106 mother-infant dyads at psychosocial risk (poverty, alcohol or drug abuse, lack of social support, teenage mothers and maternal psychic disorder) was investigated with EPDS (maternal postpartum depressive symptoms), the CARE-Index (maternal sensitivity in a dyadic context) and PSI-SF (maternal distress). The baseline data were collected when the babies had reached 19 weeks of age.</p> <p>Results</p> <p>A hierarchical regression analysis yielded a highly significant relation between the PSI-SF subscale "parental distress" and the EPDS total score, accounting for 55% of the variance in the EPDS. The other variables did not significantly predict the severity of depressive symptoms. A two-way ANOVA with "infant gender" and "maternal postpartum depressive symptoms" showed no interaction effect on maternal sensitivity.</p> <p>Conclusions</p> <p>Depressive symptoms and maternal sensitivity were not linked. It is likely that we could not find any relation between both variables due to different measuring methods (self-reporting and observation). Maternal distress was strongly related to maternal depressive symptoms, probably due to the generally increased burden in the sample, and contributed to 55% of the variance of postpartum depressive symptoms.</p

Analysis of physical pore space characteristics of two pyrolytic biochars and potential as microhabitat

Background and Aims Biochar amendment to soil is a promising practice of enhancing productivity of agricultural systems. The positive effects on crop are often attributed to a promotion of beneficial soil microorganisms while suppressing pathogens e.g. This study aims to determine the influence of biochar feedstock on (i) spontaneous and fungi inoculated microbial colonisation of biochar particles and (ii) physical pore space characteristics of native and fungi colonised biochar particles which impact microbial habitat quality. Methods Pyrolytic biochars from mixed woods and Miscanthus were investigated towards spontaneous colonisation by classical microbiological isolation, phylogenetic identification of bacterial and fungal strains, and microbial respiration analysis. Physical pore space characteristics of biochar particles were determined by X-ray μ-CT. Subsequent 3D image analysis included porosity, surface area, connectivities, and pore size distribution. Results Microorganisms isolated from Wood biochar were more abundant and proliferated faster than those from the Miscanthus biochar. All isolated bacteria belonged to gram-positive bacteria and were feedstock specific. Respiration analysis revealed higher microbial activity for Wood biochar after water and substrate amendment while basal respiration was on the same low level for both biochars. Differences in porosity and physical surface area were detected only in interaction with biochar-specific colonisation. Miscanthus biochar was shown to have higher connectivity values in surface, volume and transmission than Wood biochars as well as larger pores as observed by pore size distribution. Differences in physical properties between colonised and non-colonised particles were larger in Miscanthus biochar than in Wood biochar. Conclusions Vigorous colonisation was found on Wood biochar compared to Miscanthus biochar. This is contrasted by our findings from physical pore space analysis which suggests better habitat quality in Miscanthus biochar than in Wood biochar. We conclude that (i) the selected feedstocks display large differences in microbial habitat quality as well as physical pore space characteristics and (ii) physical description of biochars alone does not suffice for the reliable prediction of microbial habitat quality and recommend that physical and surface chemical data should be linked for this purpose

Gold-FISH: A new approach for the in situ detection of single microbial cells combining fluorescence and scanning electron microscopy

A novel fluorescence in situ hybridisation (FISH) method is presented that allows the combination of epifluorescence and scanning electron microscopy (SEM) to identify single microbial cells. First, the rRNA of whole cells is hybridised with horseradish peroxidase-labelled oligonucleotide probes and this is followed by catalysed reporter deposition (CARD) of biotinylated tyramides. This facilitates an amplification of binding sites for streptavidin conjugates covalently labelled with both fluorophores and nanogold particles. The deposition of Alexa Fluor 488 fluoro-nanogold–streptavidin conjugates was confirmed via epifluorescence microscopy and cells could be quantified in a similar way to standard CARD–FISH approaches. To detect cells by SEM, an autometallographic enhancement of the nanogold particles was essential, and allowed the in situ localisation of the target organisms at resolutions beyond light microscopy. Energy dispersive X-ray spectroscopy (EDS) was used to verify the effects of CARD and autometallography on gold deposition in target cells. The gold-FISH protocol was developed and optimised using pure cultures and environmental samples, such as rice roots and marine sediments. The combination of epifluorescence and scanning electron microscopy provides a promising tool for investigating microorganisms at levels of high resolution. Correlative characterisation of physicochemical properties by EDS will allow for the analysis of microbe-surface interactions

Evaluation of Strategies to Separate Root-Associated Microbial Communities: A Crucial Choice in Rhizobiome Research

Plants shape distinct, species-specific microbiomes in their rhizospheres. A main premise for evaluating microbial communities associated with root-soil compartments is their successful separation into the rhizosphere (soil-root interface), the rhizoplane (root surface), and the endosphere (inside roots). We evaluated different approaches (washing, sonication, and bleaching) regarding their efficiency to separate microbial cells associated with different root compartments of soil-grown rice using fluorescence microscopy and community fingerprinting of 16S rRNA genes. Vigorous washing detached 45% of the rhizoplane population compared to untreated roots. Additional sonication reduced rhizoplane-attached microorganisms by up to 78% but caused various degrees of root tissue destruction at all sonication intensities tested. Treatment with sodium hypochlorite almost completely (98%) removed rhizoplane-associated microbial cells. Community fingerprinting revealed that microbial communities obtained from untreated, washed, and sonicated roots were not statistically distinguishable. Hypochlorite-treated roots harbored communities significantly different from all other samples, likely representing true endospheric populations. Applying these procedures to other root samples (bean and clover) revealed that treatment efficiencies were strongly affected by root morphological parameters such as root hair density and rigidity of epidermis. Our findings suggest that a careful evaluation of separation strategies prior to molecular community analysis is indispensable, especially when endophytes are the subject of interest

Microbial life on a sand grain: from bulk sediment to single grains

Globally, marine surface sediments constitute a habitat for estimated 1.7 x 10(28) prokaryotes. For benthic microbial community analysis, usually, several grams of sediment are processed. In this study, we made the step from bulk sediments to single sand grains to address the microbial community directly in its micro-habitat: the individual bacterial diversity on 17 sand grains was analyzed by 16S ribosomal RNA gene sequencing and visualized on sand grains using catalyzed reporter deposition fluorescence in situ hybridization. In all, 10(4)-10(5) cells were present on grains from 202 to 635 mu m diameter. Colonization was patchy, with exposed areas largely devoid of any epi-growth (mean cell-cell distance 4.5 +/- 5.9 mu m) and protected areas more densely populated (0.5 +/- 0.7 mu m). Mean cell-cell distances were 100-fold shorter compared with the water column. In general, growth occurred in monolayers. Each sand grain harbors a highly diverse bacterial community as shown by several thousand species-level operational taxonomic units (OTU)(0.97). Only 4-8 single grains are needed to cover 50% of OTU0.97 richness found in bulk sediment. Although bacterial communities differed between sand grains, a core community accounting for 450% of all cells was present on each sand grain. The communities between sediment grains are more similar than between soil macroaggregates

Measuring prerequisites and effects of preventive intervention in early infancy

In Germany early intervention has not been systematically implemented in the regular service delivery and the existing programs have not been profoundly evaluated. Due to serious child protection cases the German Federal Ministry for Family Affairs, Senior Citizens, Women and Youth participated in a federal action program named "Early Prevention and Intervention for Parents and Children and Social Warning Systems" in 2007. Within this framework several preventive intervention programs were started funded by the government, respectively the National Centre on Early Prevention (NZFH). Angelika Schöllhorn will present the conclusions of semi-structured interviews on child protection, cooperation and networking with experts in the health care and child welfare system (N=26). The findings show how to cooperate effectively and what is necessary to start a positive communication and collaboration. They demonstrate the need of working on appropriate basic conditions (e.g., mutual appreciation, regular exchange of information) and on targeted methods and agreements for case-management. Melanie Pillhofer will contribute longitudinal evaluation data of an attachment-based intervention in a quasi-experimental control group design within the project ‘A Good Start to Children’s Life’. The developmental outcomes of the mother-childpairs in the intervention group (N=63) were compared to those in the control group (N=33) at 5 measurement points during the first year of baby’s life. Initial analyses indicate the effectiveness of the intervention. Tanja Jungmann will present longitudinal data from a randomized controlled trial evaluating the effectiveness of the German early intervention project ‘Pro Kind’ in a total sample of N=755 financially and socially disadvantaged mothers and their children. Self- and observer based-ratings of maternal competencies are related to developmental outcomes of the children at 6, 12 and 24 months of age. Data analyses show higher maternal competencies as well as better child developmental outcomes for treatment participants by trend. Andreas Eickhorst will present longitudinal evaluation data of the prevention program "Nobody falls through the net" with home visits (starting shortly after birth) in a control group design (N = 2 x 150). Especially the baby’s social development in the intervention group showed good improvement at 1 year of age. As a conclusion Carlo Schuengel will facilitate sharing of views and experiences among the participants of the symposium regarding the role that research findings concerning the prerequisites and the effects of preventive intervention play in policy and practice.Nurturing Role Questionnaire) at 32 weeks of pregnancy (T1) and 3 months after birth (T2). Prenatally (at T1), these mothers stated that they would prefer to breastfeed as opposed to bottle-feed their infants. With respect to the postnatal breastfeeding questionnaire (at T2), mothers rated on 5-point Likert scales whether they 1) experienced breastfeeding as very difficult to very easy and 2) whether they experienced breastfeeding as very tiring to not tiring. The preliminary results of two hierarchical regression analyses, with PSE T1 scores entered first, indicated that mothers who experienced breastfeeding as easier or less tiring increased in PSE from T1 to T2 (respectively = .16, p < .05 and = .18, p < .01). PSE scores at both time points were not related to breastfeeding at T2. A subset of the mothers (n = 77) stopped to breastfeed their infants before three months of age. The mothers who indicated that they stopped earlier than planned had marginally lower PSE scores at T2 as opposed to mothers who did not stop earlier than planned (p = .08). For health care practices, the current findings emphasize the importance of supporting mothers’ early experiences with breastfeeding, especially since success-based efficacy beliefs are related to positive parenting and child outcomes